This application seeks to determine the factors associated with progression of sub-clinical atherosclerosis and to evaluate the associations between the progression of sub-clinical atherosclerosis and the development of clinically manifest atherosclerosis. Changes in sub-clinical atherosclerotic disease are measured noninvasively using high resolution B-mode ultrasound and presented as changes in wall thickness (in millimeters) of the carotid artery (carotid IMT). Carotid IMT is well recognized as a measure of atherosclerotic burden. Progression of disease is hypothesized to precede the development of clinical events. The current application is also designed to be able to compare progression of carotid IMT with changes in coronary calcium score, a measure of coronary artery disease. Development of clinical atherosclerosis is evaluated by onset of clinical events (myocardial infarction, stroke, angina.) in an established cohort with a broad age-distribution and a multi-ethnic composition (MESA: Multi-Ethnic Study of Atherosclerosis). As compared to previous published works on the topic, this application offers the opportunity of measuring atherosclerosis across a broad age distribution and in a multi-ethnic cohort using state-of-the-art technologies. [unreadable] [unreadable]